There are several related standards for DVDs published by the ECMA organization that are in common use today. These standards include ECMA-267 (2nd Ed., December 1999), entitled “120 mm DVD—Read-Only Disk,” ECMA-268 (December 1997), entitled “80 mm DVD—Read-Only Disk,” ECMA-272 (2nd Ed., June 1999), entitled “120 mm DVD Rewritable Disk (DVD-RAM),” and ECMA-274 (April 1998), entitled “Data Interchange on 120 mm Optical Disk Using +RW Format—Capacity: 3,0 Gbytes and 6,0 Gbytes,” all of which are incorporated herein by reference in their entirety. Some of these standards have been adopted by the International Standards Organization as ISO/IEC standards.
Digital video disks are a digital storage media, unlike conventional videotape. Therefore copies of such digital material contain all of the information of the original and are a frequent target for pirates (copyright infringers) who make unauthorized copies or otherwise misuse same.
The present invention is directed to a particular aspect of the security problem of DVDs. Specifically, there is a need for a DVD player that only plays proprietary DVDs, does not play standard DVDs, where the proprietary DVDs cannot be copied and the proprietary DVDs do not play on standard DVD players. Thus this is a “closed” system involving proprietary format DVDs and associated players. (In this description, the term “DVD player” is used to refer to any DVD drive or playback system.)
Any such security system must be relatively inexpensive to implement (since these are consumer players), and must be robust so as to prevent copying, and not interfere with playing and enjoyment of the DVD program material. The cost requirement is especially restrictive since even a few dollars of added cost are problematic in consumer electronics. Therefore, well-known methods such as encryption may be problematic since they may require inclusion in the player of a dedicated decryption integrated circuit. Since the decryption must be performed in real time, software decryption is generally less useful in this context.